1. Field of the Invention
This invention in one embodiment relates to a fiber cement article that is locally reinforced by a material to assist in the handleability, performance and durability of the article.
2. Description of the Related Art
The market for fiber cement siding for new home construction and home refurbishing markets in the United States is presently strong, due in large part to favorable economic conditions and the durability of fiber cement.
Siding materials have traditionally been either solid or thin resilient materials. Vinyl and aluminum are two common examples of thin resilient siding materials. Vinyl siding is a thin resilient material that is shaped into the desired profile in a plastic state after extrusion of a compounded hot melt. Vinyl siding is commonly about 0.040 to 0.080 inches thick. However, vinyl presents problems as a plank material because it has a high rate of thermal expansion, which is undesirable for a product exposed to a wide range of temperatures. Aluminum siding is another example of a thin shaped product and typically has a thickness of about 0.010 to 0.030 inches. The vinyl and aluminum profiles often have an installed shape similar to traditional solid wood siding, but often include an interlocking feature to assist with the ease of installation. The interlocking profiles are usually engaged in an upward motion against gravity.
It is aesthetically pleasing for siding materials in the form of horizontal planks or laps to have a strong “shadow line” or perceived thickness such that individual planks can be discerned from a distance. This is evident from the design trends of thin vinyl or aluminum siding panels, which can be molded or extruded to give the appearance of thick, individual wood planks.
There are a number of different solid siding materials that are used in the construction and refurbishing industry. Wood siding, hardboard and fiber cement siding are examples of commonly used solid siding materials. Wood tends to lack durability and is susceptible to burning and termite attack and is not sufficiently durable in moist environments, e.g., it rots upon prolonged exposure to water. The siding shapes of solid materials are usually formed by saw cutting, machining or routing from a starting rectangular shape. A thick shadow-line or thick bottom edge of a solid siding is usually attained by starting with a solid rectangular shape of at least the thickness of the finished bottom edge of the siding. The solid siding is then machined or cut into the desired structure
While panels and planks made from wood, wood composites, and fiber-reinforced cementitious materials are inherently solid and thick, further increases in thickness of the fiber cement are not practical for reasons of material cost, weight and handling characteristics of long siding planks. Rather, an assembly that allows the use of less material while maintaining perceived thickness when installed would be beneficial. Thus, what is needed is a more efficient design of siding with a thick bottom edge to create the traditional deep shadow line with a more efficient use of material.
In addition, what is needed is a way to form a vertically-installed stackable siding plank that secures the bottom edge from lateral forces and has hidden nailing for improved aesthetics under the lap of the siding planks. In addition, what is needed is a stackable siding as described above with the exterior durability of fiber cement that is more easily machined than traditional medium density fiber cement. Furthermore, what is needed is a siding that installs with ease, maintains a constant gauge of plank rows along the length of the siding and between rows of siding and preferably resists penetration of wind driven rain through the plane of the siding.
The handleability of a siding plank is a combination of the weight, stiffness, and elasticity of the plank. Although a siding plank should be self-supporting when balanced flat upon a support point, thin fiber cement siding planks manufactured by traditional methods can be brittle and break during manual transport. While thin fiber cement siding planks could be transported by handling the edges of the planks, this slows the installation process. Therefore, what is needed is a way to improve the handleability of thin fiber cement planks.
Resistance to the effects of water and biological attack, low density, and good dimensional stability make fiber cement useful in residential and commercial building applications. However, the tensile strength of fiber cement is low relative to other building materials such as steel, aluminum, wood, and some engineered plastics. The range of application for fiber cement products could be greatly extended if fiber cement articles could be reinforced in key areas where additional tensile or impact strength is required for a specific application. What is needed is a way to provide localized reinforcement to fiber cement articles.